Many accessories like stocks and side saddles will interchange, but it's "iffy" on internal parts like trigger parts, etc.
Magazine extensions will be a problem because of the longer magazine tube on the Chinese guns. American extensions will stick out beyond the muzzle by several inches.

The Chinese guns are very close copies of the Remington, but the Remington is made in America to SAE specs, the Chinese guns are metric.
When you get two guns made by different makers in different countries, no matter how close they are some fitting will likely be needed, and some parts just may not work out at all.

Bottom line is; all you can do is test fit whatever you want to replace and hope it fits and functions.
If you're thinking of buying a Chinese gun and replacing a bunch of parts with Remington parts, this may not work out so don't count on it.